Tuesday, September 25, 2007

All Colleges ...

After our recent trip visiting liberal arts colleges, I now know that at every liberal arts college in America:

It is very safe--even if students make a point of locking the doors of their rooms when they are not in them.

Students are not competitive and don't worry about or compare grades--unlike every other college.

Students are helpful and friendly to each other--unlike other colleges.

The nearby big city is a center for cultural activities, but students practically never go there because there is so much happening on campus.

All professors are unusually accessible.

All teaching is done by professors, not graduate students--even if there are (undergraduate) teaching assistants who do some teaching (language labs) solo and assist with science labs.

The president of the school is friendly, accessible, lovable, and not a stuffed shirt.

Why Colleges Are Expensive

The cost of college has increased faster than prices in general over recent decades. After spending eight days visiting four colleges--all good liberal arts schools--that my daughter is interested in, I have at least two pieces of an answer as to why.

1. Such schools practice extensive price discrimination, I think more than in the past, so tuition substantially overstates the real cost. Judging by some figures I got at one school, the average student receives scholarship support equal to about a quarter of tuition.

2. The quality of what students get, and thus the cost of providing it, has gone up.

I should add that I have no idea whether the quality of the education has gone up--knowing that would require some reasonable measure of what students know coming in and what they know going out. But the environment in which they are educated is more luxurious, and more costly, than it was. A few examples:

All of the schools, so far as I could tell, provide the equivalent of free taxi service in and near campus, usually from the security department, to any student who calls in and says that he is worried about his safety--and in some cases to any student for any reason. Details vary, and in one case the service was provided by the town rather than the college.

The food service ranges from better than I remember to luxurious.

At one college, practically every floor has not only a resident assistant (student) but a "Wellness advisor" (also student--these are jobs with which students help pay tuition). The same college had both an "Office of the Consultant for Sexual Misconduct Services" and a "Gender and Sexuality Center," in different buildings.

At one college, when I asked about help for students finding summer jobs in their field, I was told that students could volunteer as unpaid interns--and receive a stipend from the college.

The college athletic facilities were more like a high end athletic club/fitness center than what I remember--and I went to Harvard, the richest school in the country then and now.

Expenditure on services arguably related to education has increased too. There are writing centers, where students doing papers can go to get help from (paid) upper classmen. There is the equivalent for math. Class sizes are very small. How much good this does in terms of outcomes I don't know. But I expect it makes the learning experience pleasanter.

To be fair, all of these were high end schools--six top liberal arts colleges, one top university (not all visited on this trip).

The general impression was of a gold plated education--cost no object. It isn't surprising that it's expensive.

Monday, September 24, 2007

Is the Warren Jeffs Case Religious Prosecution?

I haven't followed the case very closely, but it seems a distinctly strange one. Jeffs is charged with being an accessory to rape. The person who, on the prosecution's theory, committed the rape isn't being charged with anything. Jeffs' crime, so far as I can tell, is using his authority as a religious leader to persuade a girl into a marriage that she now says she didn't want. That might be a good reason not to accept his religion, but treating it as a felony strikes me as a considerable stretch.

What happens if we we apply the same legal theory to a more respectable religion, say the mainline LDS? Mormons are expected to pay a substantial part of their income as tithes. One can easily imagine an ex-Mormon who grew up in a small town where everyone was a member of the church testifying that he paid his tithes because of religious and social pressure, even though he never wanted to. If true, does that make the local bishop an accessory to robbery or extortion?

Suppose Jeffs is convicted. Isn't the clear implication that preaching certain religious doctrines, such as the authority of fathers over daughters and husbands over wives, is now illegal, at least if people believe the preaching and act on it?

Am I missing something?

Saturday, September 22, 2007

Imperfect Information and Suboptimal Design

I have been been doing online research on digital cameras in an attempt, so far unsuccessful, to persuade myself to replace my beloved pocket digital camera with the latest model in the same line. In doing so I came across an interesting analysis of what is wrong with the current generation of small cameras and why.

Small cameras have small sensors, which leads to a tradeoff between pixel count and sensitivity. The designer can divide the sensor into lots of individual units, giving the camera a high pixel count but making each unit small. Or he can design it with fewer but larger units. Smaller units are less sensitive, meaning that they either don't pick up an image with low light or pick it up with noise, giving a poor quality image.

The number of pixels in the image a camera produces is close to, although not entirely, an objective fact, routinely included in brief summaries of a camera's characteristics. The sensitivity is a subtler issue. A manufacturer or reviewer can report the highest sensitivity—the equivalent of ASA numbers on film—that the camera can operate at. But the manufacturer can increase that number without improving the camera by accepting more noise in the images. A good review will include a discussion of the quality of the image, and examples, but most consumers are unlikely to look for or use that sort of detailed information.

That gives the manufacturer an incentive to design the camera with more than the optimal pixel count at the cost of lowered sensitivity and lowered quality of image. He is trading off two desirable features only one of which is easily observed by the consumer, hence will put too much weight on that one. Arguably the result is a seven or eight megapixel camera—higher resolution than most photographers most of the time have any use for—that takes lower quality pictures than an otherwise similar five mexapixel camera

I don't know enough about cameras or the camera industry to judge whether the analysis I have just offered is true but I see no reason why it couldn't be. That raises an interesting question. Are there other products for which the same problem exists? Are there other situations where a producer must trade off two desirable characteristics, one of which is much more readily measured by consumers than the other, and produces as a result a suboptimal design?

One possibility that occurs to me is the tradeoff in automobile design between miles per gallon, achieved in part by making a car lighter, and ability to survive a crash. Other suggestions?

Sunday, September 16, 2007

Judging Colleges: An Economist's Tactic

In evaluating sources of information, one of my standard tactics is to try to find some overlap between what the source covers and what I already know and judge the quality of the source, hence the reliability of what it covers that I don't already know, accordingly.

Currently, we are looking for a college for our daughter, and it occurs to me that I am following a closely similar tactic there. One of the things I know a good deal about is economics. So one way of evaluating a college is by what I can judge of its economic department.

This approach was suggested to me by a conversation with an economist at one of the colleges we visited. She commented on how hard it was to teach the economics of pollution to students who regarded pollution not as a cost but as a moral evil and were thus very resistant to the idea that there was some (non-zero) optimal level of pollution. Talking with her, it occurred to me that in a school dominated by left-wing orthodoxy, a good economist must feel under siege--and thus that seeing to what degree economists at such schools preferred economics to political orthodoxy was a useful measure of the general temper of the school, in particular the tolerance of its internal society for intellectual diversity.

The approach isn't limited to left-wing schools, although as it happens all of the (elite liberal arts) schools we are currently considering are left wing. It is, I think, possible to be both a good economist and a conservative, a liberal, perhaps even, for some senses of the term, a socialist. But it is impossible, or at least very difficult, to be a good economist and an orthodox conservative, liberal, or socialist. There are simply too many political positions incorporated in each ideology that depend for their force on bad economics. That was the point I took from the conversation already described. I don't know if the professor in question regarded herself as a conservative, a liberal, or a centrist. But it was clear that she regarded herself first as an economist.

So far, investigating economics departments online, I have found only one where it seemed fairly clear that the members were left wingers first and economists second, if at all. I described that conclusion to my daughter and she decided to cross it off her list.

Curious readers may ask whether it is possible to be a good economist and an orthodox libertarian. I think that depends on the definition of an orthodox libertarian. For some definitions I think it is not. Some of the reasons are, I hope, apparent in part IV of my Machinery of Freedom (2nd edn).

Wednesday, September 12, 2007


Why do we tip waiters, taxi drivers, and others? Why is tipping a common custom in some societies but not in others?

The obvious economic explanation is that tipping provides a way in which the customer's information on quality of service can be used to reward good service and penalize poor. That explains why tipping is not limited to unusually good service; if the tip for average service is zero, the customer cannot reduce it further to punish unusually poor service.

This explains why we should tip but not why we do. A regular customer at a restaurant may regard the benefit as a private good, an incentive not to provide good service but to provide good service to him. But that does not apply to the passenger in a taxi, who is unlikely to ever see the driver again, or to the traveler who eats at a different restaurant every night. Yet they too tip.

Looking at the practice from the perspective of tipper rather than tippee suggests a different sort of explanation. By tipping we demonstrate, to ourselves and others, our willingness to adhere to social norms, even at some cost. And at the same time we get the pleasure of generosity.

Not only do we get to be generous, we get, in an odd sense, to be generous for free. If tipping were not customary restaurants would have to pay their waiters more. Instead of paying $11.50 for dinner in a world without tipping I pay $10 plus a $1.50 tip. I could stiff the waiter and save $1.50, so not doing so lets me feel both honest and generous, but on average my dinner costs me no more than it would if tipping were not customary.

This may explain why tipping is less common in Europe. Europeans, judging at least by my casual observation, are more concerned than Americans with issues of class and status. What an American sees as an opportunity to demonstrate his honesty and generosity, a European may see as a way of claiming superior status--the diner playing the role of the aristocrat tossing crusts to starving peasants. I think that fits the tone of some exchanges on the subject I have seen online between Europeans and Americans.

Friday, September 07, 2007

Wanted: A Title

I have a book manuscript, currently webbed, to be published by Cambridge University Press; at the moment I'm waiting to get my final draft back from them with comments. The book deals with possible technological revolutions over the next few decades and their implications. The working title is "Future Imperfect."

The title is intended as a play on the grammatical and the literal sense of the words. The literal point is that, while I am on the whole a technological optimist, I recognize that technological progress could have bad as well as good effects and discuss in the book how that can and might happen.

My editor thinks, probably correctly, that the title does not give an adequate clue to what the book is about, hence that it would be useful to combine it with some more informative subtitle. I am looking for suggestions.

"Technological revolutions that might happen and what to do about them" is one possibility, but I would like to do better.

Comments on the webbed draft could also be useful.

Tuesday, September 04, 2007

Preventing Wrong Numbers

Our phone number begins 244. A local business that rents out apartments begins 224. We get a lot of phone calls from people looking for apartments.

What might a phone company could do to prevent such problems? One possibility is to divide customers into two categories. Category A includes all customers, mostly commercial, who get a lot of phone calls from strangers. Category B includes all customers, mostly residential, who are likely to be bothered by wrong numbers. Assign numbers to the two groups in a way that makes it unlikely for an error in dialing a category A number to convert it into a category B number.

An alternative, starting with existing numbers, would be to calculate for each number its risk of being dialed by mistake. The calculation has three stages:

1. Research on what sort of errors people make in dialing--transposing, dialing an adjacent digit, and the like--and how likely they are.

2. For each phone number X, sum over all other numbers Yi the probability of misdialing X while trying to dial Yi times the number of calls per day that Yi currently receives.

3. Make a list of X's for which the sum is low--numbers unlikely to be misdialed--and offer them to customers at a premium price.